1. Field of the Invention
The invention relates to eyeglasses, more particularly to a turning mechanism of a temple with respect to a bracket having no hinge.
2. Description of the Related Art
There has been hitherto employed in eyeglasses a hinge serving as a turning mechanism for pivotally coupling between a bracket integrated with a front frame and a temple.
However, screws, bolts and the like serving as shafts of the hinge of the eyeglasses of this type have been loosened by frequently pivoting the temple with respect to the temple with respect to the bracket, so that the temple has been rickety. Further, there has been a case where bolts which were loosened inadvertently were lost.
Accordingly, it was necessary to fasten screws periodically using a driver for exclusive use, which has been however very troublesome.
To this end, there have been developed turning mechanisms which are different from the turning mechanism using the hinge, namely, developed several kinds of turning mechanisms each having a simple construction having no screw, bolt, and the like.
Among them, there are some turning mechanisms each having an engagement construction wherein a bracket and a temple are pivotally engaged with each other. For example, there is a turning mechanism having a hinge construction as disclosed in Japanese Utility Model Registration No. 3031979, which comprises a hollow cylindrical shaft supporting housing fixed to a lug (so-called bracket) and a shaft fitted to a temple wherein the shaft supporting housing pivotally supports the shaft of the temple.
A friction member in coated onto the inner surface of the shaft supporting housing so that a user feels moderation when turning the temple, thereby preventing the temple from falling down, namely, freely turning toward the bracket because the shaft receives a resistance force.
On the contrary, a friction member fitted to a base end of the temple contacts the inner surface of the shaft supporting housing, thereby preventing the temple from freely tuning toward the bracket likewise.
In these cases, there is an advantage that resistance force is applied to the temple for presenting the free turning of the temple with respect to the lug or bracket. Since the friction member is worn when the temple is repetitively turned with respect to the lug, there is a drawback that the friction force is gradually decreases, resulting in the hindrance of free turning prevention function of the temple with respect to the bracket.
Further, there is another drawback that if a friction force is applied to the temple for recovering the free turning prevention function, the lug and the temple have to be replaced with another lug or temple, which costs much. It is needless to say that it was impossible to regulated a resistance force applied to the temple.